Yes I downloaded from the oficial chuwi forum. I am using Mac to transfer files to USB and I have used these programs to try and extract the .rar files so far:
WinZip, The unarchiver, Zip Express, Stuffit, Archiver, Better Zip, and I zip.
And sadly none of them work. I have also tried to download the .rar files again with the same result.

Hi thank you for the reply,
I finally used a PC to prepare and it didn't work..
Anyway it doesn't seem to matter any more now that the tablet wont even turn on.
It is still under warranty can you tell me what I can do?.. not even sure it is worth it because of shipping cost to send it back to China..

Before giving up and losing your investment you should contact the seller informing him of the problem. The seller will give you some solution, such as a repair in your country, a compensation to obtain another one or a change of your tablet.
In the case of shipping to China, I can tell you from experience, that from my country, Spain, the amount of the refund is 26 euros, about 30 US dollars.